Hundreds of armed vigilantes took control of a Mexican town in the western coastal state of Guerrero, arresting local cops and conducting searches and handing the accused over to state prosecutors in response to the killing of a vigilante leader Monday.

The area’s self-described “community police” have set up improvised checkpoints in the town of Tierra Colorado, which is located between Mexico City and Acapulco. They arrested 12 police officers and the town’s former director of public security, in addition to wounding tourists who refused to stop at roadblocks.

The vigilantes say they are fighting violence, kidnappings and extortions carried out by drug cartels, sometimes with the cooperation of or lack of opposition from local police. Officials have largely tolerated vigilante groups because they are difficult to control in rural areas, The Associated Press reports.

The vigilantes accuse the ex-security director of participating in the killing of vigilante leader Guadalupe Quinones Carbajal, 28, on behalf of local organized crime groups and dumping his body in a nearby town on Monday. They reported seizing several high-powered rifles from his car, and vigilantes were seen toting a number of sophisticated assault rifles on Wednesday, although it was not clear if all had been taken from the ex-security director’s car.

“We have besieged the municipality, because here criminals operate with impunity in broad daylight, in view of municipal authorities. We have detained the director of public security because he is involved with criminals and he knows who killed our commander,” said Bruno Placido Valerio, a spokesman for the vigilante group.

Placido said vigilantes had searched a number of homes in the town and seized drugs from some. They turned over the ex-security director and police officers to state prosecutors, who agreed to investigate their alleged ties to organized crime.